Optimization of the lightning warning model for distribution network lines based on multiple meteorological factor thresholds

Abstract

Lightning is one of the frequent natural disasters, which seriously affects the secure and stable operation of the power system, especially the distribution network lines with weak reliability. In order to improve the power supply reliability of the distribution network, higher requirements are put forward for the accuracy of lightning warning. Therefore, this paper establishes a lightning warning model based on comprehensive multi-meteorological factor thresholds and analyzes the meteorological factor data such as atmospheric field strength, echo intensity, echo-top height, and vertical cumulative liquid water content under thunderstorm weather. The threshold value of each factor warning is obtained, and the corresponding threshold weight is calculated by the entropy weight method. According to the weight of each threshold, the comprehensive threshold index of lightning warning is obtained, and the lightning warning is based on this index. A total of 105 lightning data from May to June 2022 in Nanchang city were analyzed as samples. The thresholds of atmospheric field strength, echo intensity, echo-top height, and vertical cumulative liquid water content were 1.2 kV/m, 40 dBZ, 8 km, and 5.2 kg·m−2, respectively. The corresponding weights of each factor were 0.4188, 0.2056, 0.2105, and 0.165, respectively. This model was used to warn a thunderstorm event in July 2022 in Nanchang area. The success rate of the model warning was 0.91, the false alarm rate (FAR) was 0.11, and the critical success index (CSI) was 0.80. Compared with the single-factor threshold lightning warning model, the warning FAR is decreased by 6%, and CSI is increased by 14% while ensuring the high warning success rate.

Theoretical study on Stark effect of Rydberg atom in super low frequency electric field measurement

“…As an important electrical parameter of the power system, the electric field signals contain information about the operation of lines and electrical equipment. The electric field measurement is widely used in electrical equipment insulation status assessment [1,2], power system electromagnetic environment assessment [3,4], lightning warning [5,6] and other occasions. Traditional electric field sensors based on electrical and optical principles face insurmountable limitations in the optimisation of measurement sensitivity, accuracy, operating bandwidth, and miniaturisation.…”

“…The figure below shows the relationship between rR(r) and r (the unit is Bohr radius a 0 ) when the principal quantum number n = 25 and the angular quantum number l = 0, 1, 2 (only the results of solutions to three wave functions are listed, in fact, for each n, there are l = n-1 wavefunctions. ), Furthermore, Equations(6)(7)(8)(9)(10) are combined to solve the Stark structure diagram of Rydberg atom under the action of external field. At present, most electric field measurements based on Rydberg atoms use two-photon excitation energy level schemes.…”